core: Do not flush hypervisor TLB on unrelated page table changes

core: Do not flush hypervisor TLB on unrelated page table changes

Only when working against the hypervisor page table in page_map_create
and page_map_destroy, we actually need to flush TLBs. Other page tables
require arch-specific flushings that we perform on arch_config_commit.

This measurably speeds up Jailhouse activation, e.g., when a significant
number of EPT and VT-d page table changes are performed.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>